Figure 3. Relation between grain size, Cl content and fission track age. (A) Fission track age versus number of squares on counting grid (quads). Older, Cl-rich grains (solid blue squares) are associated with 16 or less quads (silt sized); younger, Cl-poor grains (solid red dots) span a broader range of quads (silt to sand size). Vertical bars represent one standard deviation on grain age. (B) Cl content (atoms per formula unit) of age grains versus number of quads. Plot shows that high Cl grains (except for three outliers - see Fig. 1) are associated with a smaller number of quads than lower Cl grains.